ISSN:1424-8581    

DOI:10.1159/000131580

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

A complex four-break rearrangement between chromosomes 4 and 13 was ascertained in a 10-year-old mentally retarded girl. The rearrangement was inherited from the phenotypically normal mother, who had an inverted insertion of part of the long arm of chromosome 4 into the long arm of 13 and, in addition, a pericentric inversion of the deleted 4. Meiotic crossing-over between the normal and the inverted 4 resulted in a recombinant chromosome 4, which was inherited by the proband, together with the 13/4 insertion. In this way the proband became monosomic for 4q35→qter and trisomic for 4pter→4p15, but she showed only minor physical malformations, as compared with other reports on the trisomy 4p syndrome. The cytogenetic findings were difficult to describe using the ISCN nomenclat

ISSN:1424-8581    

DOI:10.1159/000131581

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

Djungarian hamster and mouse L-53 cell lines with 150–200-fold increases in resistance to colchicine contained marker chromosomes with a long homogeneously staining region (HSR). In two clones of Djungarian hamster cells, an HSR was located in the long arm of chromosome 4; in another Djungarian hamster cell line and in mouse L-53 cells, an HSR was located in unidentified marker chromosomes. During cultivation in colchicine free medium these cells lost their resistance at the rate of 2–3 x 10–2 cells per population doubling. The loss of resistance was accompanied by the disappearance of the HSR and emergence of possible double minutes (dmins). These observations suggest that colchicine-resistance is the result of gene amplification and support the idea that dmins may be derived from the HSR in these sy

ISSN:1424-8581    

DOI:10.1159/000131582

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

In previous cytogenetic studies of rabbits injected with the clastogen, streptonigrin (SN), we observed a higher incidence of chromosome aberrations in lymph node cells than in marrow cells recovered 6 h after treatment. In this study we examined several factors that may be responsible for this difference in the incidence of lesions. Results from SN pulse-treated lymphoid and marrow cultures demonstrated that the responses were different in vitro also. In addition, at higher doses of SN, lymphoid cells displayed a greater sensitivity to the drug when treated during DNA synthesis; marrow cells showed no differences in sensitivity throughout the cell cycle. Analysis of the percentage of lymph node and marrow metaphases labeled following 2, 4, or 6 h of culture in the presence of tritiated thymidine indicated that G2 was less than 2 h in lymph node cells and approximately 4 h in marrow cells. From these data we conclude that the difference in the length of G2 in the two cell types is partially responsible for the difference in the incidence of lesions 6 h after an in vivo SN exposure. However, our data also indicate that lymph node cells are innately more sensitive to the induction of lesions than are marrow cells.

ISSN:1424-8581    

DOI:10.1159/000131583

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

Double minute (dmin) chromosomes were found in 17% of bone marrow cells in a 66-year-old woman with acute myelogenous leukemia (AML) which was resistant to treatment with cytosine arabinoside and daunorubicin hydrochloride. She died within 3 weeks of developing symptoms. The cells had a range of 36 to 49 chromosomes with a mode of 47 and a variety of structural and numerical chromosome abnormalities, as well as the presence of 1 to 10 C-chromatin negative dmins. In leukemias few cases with dmins have been reported. However, we suspect other cases may have been overlooked because of the very small size of some dmins. We hope that this report will direct attention to the presence of dmins in leukemic cells and, in particular, stimulate attempts to determine if there is a correlation between their presence and the resistance of the cells to chemotherapy or the rate of disease progression.

ISSN:1424-8581    

DOI:10.1159/000131584

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

Five cases of ovarian adenocarcinoma, three cases of endometrial adenocarcinoma, and one case of transitional cell carcinoma of the bladder have been studied for expression of silver-stained nucleolar organizing regions (Ag-NORs). The modal chromosome number of these tumors varied from 37 to 72, with a wide range of chromosome numbers (13 to 150). The modal number of Ag-NORs in this sample varied from 3 to 7. Regression analysis among and between tumors demonstrated a proportionate increase in the number of Ag-NORs with increasing number of total chromosomes and increasing number of acrocentric chromosomes (r = 0.64 and 0.75, respectively). Modal assessment of Ag-NORs in both peripheral blood lymphocytes (PBLs) and cultured tumor cells in one patient revealed identical modes in normal and malignant cells. Also, no difference in the expression of Ag-NORs was observed between tumor cells obtained at biopsy and placed for 48 h in agar culture and tumor cells established in finite monolayer culture. Our study provides further evidence for a proportionate increase in Ag-NORs with increasing numbers of acrocentric chromosomes and total chromosomes.

ISSN:1424-8581    

DOI:10.1159/000131585

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

In situ hybridization of pachytene bivalents of a male Chinese hamster with 125Ilabeled rRNA permitted localization of rDNA. An analysis of the regional distribution of autoradiographic grains from 39 cells showed that rDNA sites were localized in the telomeric regions of chromosome arms 3q, 4q, 5q, 7q, 8p, and 9q. Of these, the sites on 3q, 4q, 5q, and 9q hybridized more frequently and also had significantly more autoradiographic grains than those on 7q and 8p, suggesting that the former four chromosomes had more rDNA than the latter two. The sex chromosomes did not exhibit specific labeling. Silver staining of pachytene chromosomes and sequential silver and quinacrine staining of somatic chromosomes of a second male animal permitted detection of metabolically active ribosomal genes at meiosis and at mitosis. All 12 sites were found to be potentially able to express nucleolus organizing function at meiosis, while expression by individual chromosomes was found to be variable at mitosis in this animal. Chromosomes 3, 4, and 9 showed a high degree of expression (91–97’% of cells with Ag-NORs). Chromosome 8 showed expression to a lesser degree (60% of cells with Ag-NORs), while chromosome 7 showed the weakest expression (29% of cells with Ag-NORs) of all chromosomes that had NORs. Expression by chromosome 5, while high (83% of cells with Ag-NORs), was probably restricted to one homolog. These results permitted two conclusions to be drawn: (1) the amount of rDNA present probably determined the frequency with which its metabolic activity was expressed, and (2) the two animals probably varied with respect to either the amount of rDNA present or its ability to express rDNA function on chromosom

ISSN:1424-8581    

DOI:10.1159/000131586

出版商:S. Karger AG    

年代:1981

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000131587

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

The frequency of sporadic, hypermodal chromosomal spreads in cultures of leukocytes taken from the parents of aneuploids significantly exceeds that in comparison populations. Elimination of other possibilities suggests mitotic nondisjunction as the ultimate determinant for such spreads. This possibility requires that more attention be paid to the occurrence of hypermodal spreads, especially relative to the etiology of aneuploid concepti.

ISSN:1424-8581    

DOI:10.1159/000131588

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

A female sheep with a 53, X karyotype was discovered while screening barren ewes at a commercial sheep ranch in New Mexico. She was physically normal in phenotype, in very good flesh due to freedom from nursing offspring, and her external genitalia were normal. This is the first case of monosomy X to be documented in sheep.

ISSN:1424-8581    

DOI:10.1159/000131589

出版商:S. Karger AG    

年代:1981

数据来源: Karger